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- Use vfs_ref/rel to protect a mountpoint from going away while VFS_STATFS

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is being called.  Be sure to grab the ref before we unlock the vnode to
   prevent the mount from disappearing.

Tested by:	kris
This commit is contained in:
jeff 2006-02-23 05:18:07 +00:00
parent 63c47d3ba4
commit dc6bf4c70b
2 changed files with 58 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
sys/kern/vfs_extattr.c
View File

@ -249,19 +249,20 @@ kern_statfs(struct thread *td, char *path, enum uio_seg pathseg,
struct nameidata nd;
mtx_lock(&Giant);
NDINIT(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path, td);
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, pathseg, path, td);
error = namei(&nd);
if (error) {
mtx_unlock(&Giant);
return (error);
}
mp = nd.ni_vp->v_mount;
sp = &mp->mnt_stat;
vfs_ref(mp);
NDFREE(&nd, NDF_ONLY_PNBUF);
vrele(nd.ni_vp);
vput(nd.ni_vp);
#ifdef MAC
error = mac_check_mount_stat(td->td_ucred, mp);
if (error) {
vfs_rel(mp);
mtx_unlock(&Giant);
return (error);
}
@ -269,10 +270,12 @@ kern_statfs(struct thread *td, char *path, enum uio_seg pathseg,
/*
* Set these in case the underlying filesystem fails to do so.
*/
sp = &mp->mnt_stat;
sp->f_version = STATFS_VERSION;
sp->f_namemax = NAME_MAX;
sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
error = VFS_STATFS(mp, sp, td);
vfs_rel(mp);
if (error) {
mtx_unlock(&Giant);
return (error);
@ -327,32 +330,40 @@ kern_fstatfs(struct thread *td, int fd, struct statfs *buf)
error = getvnode(td->td_proc->p_fd, fd, &fp);
if (error)
return (error);
mtx_lock(&Giant);
vp = fp->f_vnode;
#ifdef AUDIT
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
#ifdef AUDIT
AUDIT_ARG(vnode, vp, ARG_VNODE1);
VOP_UNLOCK(vp, 0, td);
#endif
mp = vp->v_mount;
if (mp)
vfs_ref(mp);
VOP_UNLOCK(vp, 0, td);
fdrop(fp, td);
if (vp->v_iflag & VI_DOOMED)
if (vp->v_iflag & VI_DOOMED) {
if (mp)
vfs_rel(mp);
mtx_unlock(&Giant);
return (EBADF);
mtx_lock(&Giant);
}
#ifdef MAC
error = mac_check_mount_stat(td->td_ucred, mp);
if (error) {
vfs_rel(mp);
mtx_unlock(&Giant);
return (error);
}
#endif
sp = &mp->mnt_stat;
/*
* Set these in case the underlying filesystem fails to do so.
*/
sp = &mp->mnt_stat;
sp->f_version = STATFS_VERSION;
sp->f_namemax = NAME_MAX;
sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
error = VFS_STATFS(mp, sp, td);
vfs_rel(mp);
if (error) {
mtx_unlock(&Giant);
return (error);
@ -4312,14 +4323,20 @@ kern_fhstatfs(struct thread *td, fhandle_t fh, struct statfs *buf)
return (error);
}
mp = vp->v_mount;
sp = &mp->mnt_stat;
if (mp)
vfs_ref(mp);
vput(vp);
if (mp == NULL)
return (EBADF);
error = prison_canseemount(td->td_ucred, mp);
if (error)
if (error) {
vfs_rel(mp);
return (error);
}
#ifdef MAC
error = mac_check_mount_stat(td->td_ucred, mp);
if (error) {
vfs_rel(mp);
mtx_unlock(&Giant);
return (error);
}
@ -4327,10 +4344,12 @@ kern_fhstatfs(struct thread *td, fhandle_t fh, struct statfs *buf)
/*
* Set these in case the underlying filesystem fails to do so.
*/
sp = &mp->mnt_stat;
sp->f_version = STATFS_VERSION;
sp->f_namemax = NAME_MAX;
sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
error = VFS_STATFS(mp, sp, td);
vfs_rel(mp);
mtx_unlock(&Giant);
if (error)
return (error);

39
sys/kern/vfs_syscalls.c
View File

@ -249,19 +249,20 @@ kern_statfs(struct thread *td, char *path, enum uio_seg pathseg,
struct nameidata nd;
mtx_lock(&Giant);
NDINIT(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path, td);
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, pathseg, path, td);
error = namei(&nd);
if (error) {
mtx_unlock(&Giant);
return (error);
}
mp = nd.ni_vp->v_mount;
sp = &mp->mnt_stat;
vfs_ref(mp);
NDFREE(&nd, NDF_ONLY_PNBUF);
vrele(nd.ni_vp);
vput(nd.ni_vp);
#ifdef MAC
error = mac_check_mount_stat(td->td_ucred, mp);
if (error) {
vfs_rel(mp);
mtx_unlock(&Giant);
return (error);
}
@ -269,10 +270,12 @@ kern_statfs(struct thread *td, char *path, enum uio_seg pathseg,
/*
* Set these in case the underlying filesystem fails to do so.
*/
sp = &mp->mnt_stat;
sp->f_version = STATFS_VERSION;
sp->f_namemax = NAME_MAX;
sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
error = VFS_STATFS(mp, sp, td);
vfs_rel(mp);
if (error) {
mtx_unlock(&Giant);
return (error);
@ -327,32 +330,40 @@ kern_fstatfs(struct thread *td, int fd, struct statfs *buf)
error = getvnode(td->td_proc->p_fd, fd, &fp);
if (error)
return (error);
mtx_lock(&Giant);
vp = fp->f_vnode;
#ifdef AUDIT
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
#ifdef AUDIT
AUDIT_ARG(vnode, vp, ARG_VNODE1);
VOP_UNLOCK(vp, 0, td);
#endif
mp = vp->v_mount;
if (mp)
vfs_ref(mp);
VOP_UNLOCK(vp, 0, td);
fdrop(fp, td);
if (vp->v_iflag & VI_DOOMED)
if (vp->v_iflag & VI_DOOMED) {
if (mp)
vfs_rel(mp);
mtx_unlock(&Giant);
return (EBADF);
mtx_lock(&Giant);
}
#ifdef MAC
error = mac_check_mount_stat(td->td_ucred, mp);
if (error) {
vfs_rel(mp);
mtx_unlock(&Giant);
return (error);
}
#endif
sp = &mp->mnt_stat;
/*
* Set these in case the underlying filesystem fails to do so.
*/
sp = &mp->mnt_stat;
sp->f_version = STATFS_VERSION;
sp->f_namemax = NAME_MAX;
sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
error = VFS_STATFS(mp, sp, td);
vfs_rel(mp);
if (error) {
mtx_unlock(&Giant);
return (error);
@ -4312,14 +4323,20 @@ kern_fhstatfs(struct thread *td, fhandle_t fh, struct statfs *buf)
return (error);
}
mp = vp->v_mount;
sp = &mp->mnt_stat;
if (mp)
vfs_ref(mp);
vput(vp);
if (mp == NULL)
return (EBADF);
error = prison_canseemount(td->td_ucred, mp);
if (error)
if (error) {
vfs_rel(mp);
return (error);
}
#ifdef MAC
error = mac_check_mount_stat(td->td_ucred, mp);
if (error) {
vfs_rel(mp);
mtx_unlock(&Giant);
return (error);
}
@ -4327,10 +4344,12 @@ kern_fhstatfs(struct thread *td, fhandle_t fh, struct statfs *buf)
/*
* Set these in case the underlying filesystem fails to do so.
*/
sp = &mp->mnt_stat;
sp->f_version = STATFS_VERSION;
sp->f_namemax = NAME_MAX;
sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
error = VFS_STATFS(mp, sp, td);
vfs_rel(mp);
mtx_unlock(&Giant);
if (error)
return (error);